Synthesis, Photophysical Properties and Self‐Assembly of a Tetraphenylethylene‐Naphthalene Diimide Donor‐Acceptor Molecule

Abstract

The development of new π‐conjugated molecular structures with controlled self‐assembly and distinct photophysical properties is crucial for advancing applications in optoelectronics and biomaterials. This study introduces the synthesis and detailed self‐assembly analysis of tetraphenylethylene (TPE) functionalized naphthalene diimide (NDI), a novel donor‐acceptor molecular structure referred to as TPE‐NDI. The investigation specifically focuses on elucidating the self‐assembly behavior of TPE‐NDI in mixed solvents of varying polarities, namely chloroform: methylcyclohexane (CHCl3: MCH) and chloroform: methanol (CHCl3: MeOH). Employing a several analytical methodologies, including UV‐Vis absorption and fluorescence emission spectroscopy, scanning electron microscopy (SEM), X‐ray diffraction (XRD), and dynamic light scattering (DLS), these self‐assembled systems have been comprehensively examined. The results reveal that TPE‐NDI manifests as distinct particles in CHCl3: MCH (fMCH = 90%), while transitioning to flower‐like assemblies in CHCl3: MeOH (fMeOH = 90%). This finding underscores the critical role of solvent polarity in dictating the morphological characteristics of TPE‐NDI self‐assembled aggregates. Furthermore, the study proposes a molecular packing mechanism, based on SEM data, offering significant insights into the design and development of functional supramolecular systems. Such advancements in understanding the molecular self‐assembly new π‐conjugated molecular structures are anticipated to pave the way for novel applications in material science and nanotechnology.